LANforge is a unified multi-protocol network traffic generation and WAN emulation application. It allows users to generate real world customer traffic in a controllable manner. The WAN emulator allows the injection of latency and other network oddities like dropped, duplicated, and re-ordered packets. LANforge includes a drag-and-drop virtual network builder that supports virtual routers, WAN links, traffic-generating nodes, and more. It provides a scriptable command line interface with Perl libraries as well as a graphical user interface.

The Grinder is a simple, pure Java load-testing
framework. Test client code is written in the
form of Java plug-ins. Sample plug-ins for testing
HTTP services are provided. It is particularly
suitable for testing BEA WebLogic Server-based
applications.

OpenLoad is a tool for load-testing Web
applications. It aims to be easy to use and
providing near real-time performance measurements
of the application under test. This is particulary
useful when you are doing optimization as you can
see the impact of your changes almost immediately.

Jot is used to print out increasing, decreasing,
random, or redundant data, usually numbers, one
per line. It can be used to generate randomness
fitting a certain pattern (eg, a random IP
address) or number sequences (useful in shell
programming). It is often distributed together
with lam and rs, sometimes under the name bsd-utils.

This program was written to help test the Open
Projects dancer-ircd. It simulates client activity
by selecting random servers to connect to and
random actions out of a list. It can handle
hundreds of simultaneous connections, and can
replay a log file of what it has previously done
in order to help isolate the actions which cause
the daemon to have problems, using methods such as
binary chops. Please note that although at this
point code is only written to test ircds, it is
hoped that this will be extended in the future to
other types of daemons.

Tcpreplay is a set of Unix tools which allows the editing and replaying of captured network traffic in pcap (tcpdump) format. It can be used to test a variety of passive and inline network devices, including IPS's, UTM's, routers, firewalls, and NIDS.

Xnee can record, distribute, and replay X (X11) protocol data. This
is useful for automated tests of applications or benchmarking of
applications. Think of it as a robot. A GUI, a Gnome Panel Applet, and a
CLI are available, as well as bash functions.

AWbot is a bot that connects to your Web site and makes URL requests
like human visitor. It's not a Web indexing robot, but a Web client
tool that emulates visitors browsing your Web site to test its
stability after a development change, its reliability, and its
response to heavy loads.